Pulling assembly for connecting a load to a pulling device

ABSTRACT

A pulling assembly where a rotary unit is acted upon by a tension-transmitting structure, such as a cable, in such a way as to tend to rotate this rotary unit in response to a pulling force which acts on the cable or other tension transmitting structure. A brake assembly coacts with the rotary unit to resist rotation thereof. Therefore, when the rotary unit is turned the force transmitted thereto will be converted into heat by the braking action.

United States Patent Kuhl [ 51 Feb. 22, 1972 [54] PULLING ASSEMBLY FOR CONNECTING A LOAD TO A PULLING DEVICE [72] Inventor: Hans Kuhl, Kornbergweg 12, Plochingen,

Germany [22] Filed: May 14, 1969 [21] Appl. No.: 824,632

[52] U.S.Cl ..242/107.3, 242/99 [51] Int. Cl ..B65h75/48 [58] Field ofSearch ..242/99, 106, 107, 107.3, 107.4, 242/1075, 156; 188/83 [56] References Cited UNITED STATES PATENTS 11,067 3/1890 Griswold ..242/ 107.3 1,695,096 12/1928 Hanses 2,896,912 7/1959 Faugier et al. 2,990,131 6/1961 Carlsson ..242/l07.4

3,059,727 10/1962 Fuchs ..188/83 X 3,182,962 5/1965 Gray ..242/99 X 3,386,683 6/1968 Howland ..242/l07.4

FOREIGN PATENTS OR APPLICATIONS 201,103 6/1958 Austria ..242/l07.3

Primary Examiner-Stanley N. Gilreath Assistant ExaminerWemer H. Schroeder Attorney-Arthur O. Klein [57] ABSTRACT A pulling assembly where a rotary unit is acted upon by a tension-transmitting structure, such as a cable, in such a way as to tend to rotate this rotary unit in response to a pulling force which acts on the cable or other tension transmitting structure. A brake assembly coacts with the rotary unit to resist rotation thereof. Therefore, when the rotary unit is turned the force transmitted thereto will be converted into heat by the braking action.

14 Claims, 5 Drawing Figures PATENIEUFEB22 I972 SHEET 2 or 4 lnveqtor Hans KUHL I/H'S Afforner PAIENTEBFEBZZ i972 I SHEET 3 [IF 4 mazuxa 2 my xx x w m mwnmmuw lnvegtor: Hans 6 m a m 1 Affo rney PULLING ASSEMBLY FOR CONNECTING A LOAD TO A PULLING DEVICE BACKGROUND OF THE INVENTION The invention relates to a device for interconnecting a mass which is to be pushed or pulled with a pulling assembly. In particular the present invention relates to a structure capable of connecting an automobile or other vehicle which is to be pulled with a pulling vehicle, or the invention may be used with a lifting structure used for raising a given mass.

There are known pulling cable assemblies to be used for pulling automobiles or other vehicles. Such known assemblies include a prestressed spring which drives a winding unit on which the cable is wound. The turning moment derived from such a spring is so small that the cable is wound up only when there is no noticeable tension acting on the cable. A greater rewinding force would provide an improper operation of this known structure because a temporary storing of energy in the rewinding spring would result in a constant acceleration of the mass which is to be pulled and a subsequent retarding in the pulling thereof, such acceleration and retarding alternating with each other. Thus, with such an arrangement it easily happens that the pulling cable rubs along the ground and even becomes situated beneath the pulled vehicle which rides over the cable. In fact under these conditions the cable can become wound upon and entangled with the vehicle which is to be pulled.

It is also known to provide, for pulling rod or pulling cable assemblies, springs or other elastic components for absorbing impacts which are encountered as when the vehicle travels over uneven ground, engages potholes or the like, or in the case where the pulled vehicle is suddenly braked. By such absorption of this impact, breaking of the connecting element or the structure fastening the latter to a vehicle is avoided. However, with this construction also when there is a sudden increase in the pulling force, the resulting impact energy is only stored in the elastic components. This will then immediately result in an undesirable acceleration of the pulled vehicle with the disadvantages discussed above necessarily following.

SUMMARY OF THE INVENTION It is accordingly a primary object of the invention to provide an assembly which will avoid the above drawbacks. In particular, it is an object of the invention to provide an assembly which will enable a pulling force to be transmitted in such a way that transmission of impact loads between the pulled mass and the pulling assembly in either direction is reliably prevented.

In addition, it is an object of the invention to provide a device of this type which will avoid any temporary acceleration of the pulled mass as a result of an impact loading which is encountered.

A more specific object of the invention is to provide for a device of the above general type an energy converter capable of converting one form of energy into another in such a way as to avoid the drawbacks set forth above.

In particular, it is an object of the invention to provide a rugged relatively inexpensive assembly which can easily be handled so as to be readily and conveniently connected between pulling and pulled objects to achieve the results of the invention.

According to the invention the pulling force is transmitted to a rotary means by way of a tension-transmitting means. A brake means coacts with the rotary means to resist turning thereof in response to the pulling force, so that the energy of the pulling force is converted into heat by the brake means.

In the case where the tension-transmitting means is in the form of a bendable element such as a cable, tape, band, or the like, then the rotary means includes a member on which such a bendable or flexible element can be wound. However, the tension-transmitting means can also take the form of an elongated bar carrying a rack the teeth of which mesh with the peripheral teeth of a rotary member in the form of a rotary gear, for example.

When an impact load is encountered, the rotary means is turned, for example by the cable which in response to such an impact load is pulled under tension and unwound from the rotary means. The brake means will now act to receive the impact energy and convert it into heat. As a result of this irreversible energy conversion, there is a reliable prevention of a subsequent conversion of the impact energy into acceleration of the load which is to be pulled. A further advantage of the assembly of the invention resides in the fact that additional connecting elements such as additional cables by means of which the assembly of the invention is connected with the load which is to be pulled and with the pulling unit can be made out of unstretchable inexpensive materials. Furthermore, such nonelastic connecting elements prevent the above-mentioned temporary acceleration of the load which is pulled.

With a preferred construction of the invention the brake means is provided with an adjusting means which can be adjusted to provide a preselected braking force or moment. In this way it becomes possible to adjust the braking force or moment in such a way that the stress resulting from impact does not produce any damage to the fastening components which interconnect the load and the pulling structure of the invention, and also in this way any additional connecting elements which may be used in a normal way will not risk the danger of becoming torn.

The rotary means can take the form of a rotary winding drum held by a suitable holder with the brake means connected between the rotary drum and the holder. Because of the possibility of achieving relatively high braking moments in a limited amount of space, it is of advantage to construct the brake means in the form of a brake composed of a series of laminations which frictionally engage each other. Moreover, with such a construction it is a simple matter to adjust the braking force simply by changing the pressure with which the brake laminations engage each other.

In order to provide for automatic rewinding of a cable or other bendable element which is unwound in response to an impact load, so that subsequent to the impact the cable will be rewound, it is of advantage to provide a clutch or similar mechanism which enables the winding unit to be turned in the rewinding direction without encountering any resistance from the braking structure. A spring or similar drive which seeks to rotate the drum in the winding direction will in such a case be dimensioned in such a way that when the pulling force diminishes, as may occur when the pulling vehicle slows down, the bendable element in the form of a cable or the like can be automatically rewound onto the drum. If an impact load is then encountered, then the cable or other flexible element is unwound from and pulled from the drum in opposition to the force of the braking means because the clutch or I similar mechanism acts to prevent a free rotary movement of the winding drum in the direction in which it is pulled by the cable when the latter is unwound in response to a pulling force. The same corresponding type of action is achieved when a rack or other tension-transmitting structure is used for rotating the rotary means in response to a pulling force.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a simplified schematic illustration of the manner in which the structure of the invention is used between pulling and pulled vehicles;

FIG. 2 is a side elevation of a winding unit provided with a braking device;

FIG. 3 is a bottom plan view of the structure of FIG. 2 as seen in the direction of the arrow X;

FIG. 4 is a transverse section of the structure of FIG. 2, taken along line AB of FIG. 2 in the direction of the arrows; and

FIG. 5 is a longitudinal sectional fragmentary elevation of another embodiment of the assembly of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 1, the pulling vehicle 1, fragmentarily illustrated at the left, is connected with the load, in the form of a vehicle 2, which is to be pulled by way of the illustrated structure which includes the pulling cable 3, the assembly 4 of the invention which acts as an energy converter, and the connecting cable 5 which serves to connect the assembly 4 of the invention with the pulled vehicle 2. The pull cable 3 is partly wound onto a rotary means in the form of a rotary drum 9 of the energy converter 4. The free end of the cable 3 serves to connect the assembly of the invention to the vehicle 1. Of course, if desired, the free end of the cable 3 could be connected to the pulled vehicle 2 while the connecting cable 5 could be connected to the pulling vehicle 1. The length of the cable 5 is selected in such a way that the assembly 4 will not drag on the ground when the cable 3 is not under tension.

The rotary means which is formed by the drum 9 is held for rotary movement by a holding means in the form of a housing made up of a pair of shelves 14 and 15. The drum 9 is provided at its circumference with a groove-shaped winding chamber 16 in which at least part of the pull cable 3 is wound. It is, however, also possible to wind on the drum 3 another cable the free end of which can be connected to a pull cable of suitable length. The inner periphery of the drum 9 is of annular configuration and defines an inner hollow space 17. Within this hollow space is situated a sleeve 19 which is fixed to the drum 9 and which has an axially splined configuration. The rotary means includes in addition to the outer part of the drum 9 on which the cable is wound an inner hub portion 20 which is provided at its exterior with an axially splined profile 21.

The outer friction plates 11 of the brake means 11, 12 have tooth peripheries received in the axial grooves formed at the inner portion 18 of the sleeve 19. These friction plates 11 alternate with inner laminations or plates 12 which respectively have inner toothed peripheries extending into the axial grooves formed at the inner member 21 which is fixed to the hub portion 20. Thus, the brake laminations 11 will necessarily rotate with the drum 9 while the brake laminations 12 will necessarily rotate with the hub 20. A nut 22, threaded onto an externally threaded end portion of the hub 20, engages one end of an annular cup spring 23 the other end of which presses against the group of laminations 11, 12 so that all of the laminations which form the brake means are pressed against the end flange 20' with an adjustable force selected according to the angular position of the nut 22 on the hub 20.

The hub 20 is formed with an axial bore 24 of noncircular or axially grooved profile, and a clutch member 25 has an elongated axial portion of matching profile received in the bore of the hub 20 for axial movement therein while being constrained to rotate therewith. This clutch member 25 is provided with an annular flange having at its surface which is directed away from the hub 20 a plurality of ratchet teeth 27. Moreover, this clutch member 25 has a projection 33 terminating in an outer convex surface and extending through the exterior of the housing shell 14 through a central opening thereof.

This projection of the clutch member 25 extends freely through an annular clutch member 28 which, for example, can be fixed to the housing and with respect to which the clutch member 25 is freely tumable. At its surface which is directed toward the flange of clutch member 25 the coacting clutch member 28 is provided with ratchet teeth 27 which coact with the ratchet teeth of the clutch member 25. Thus, it will be seen that all of these teeth are of a sawtooth configuration having short, almost axially extending flanks for each tooth as well as a relatively flat surface for each tooth which is almost located in a plane normal to the axis of the hub 20. A prestressed coil spring 26 is situated in a bore of the clutch member 25 to press on the latter for urging this clutch member 25 to the left, as seen in FIG. 4, into engagement with the clutch member 28. The right end of the spring 26 engages the inner end of a handle 34 which is fixed to the hub 20.

Within the shell 14 of the housing which forms the holder means, there is located, beside part of the drum 9 and part of the brake means 11, 12, a spiral spring one end of which, in the illustrated example, is fixed by means of a pin 29 directly with the housing shell 14 while the other end, in the illustrated example, is fixed to the drum 9 by way of a rivet 30. The rotary turning moment which is exerted on the drum 9 by the spiral spring 10 is so great that the drum will automatically wind up a predetermined length of the pulling cable 3, such as, for example, a section of pulling cable having a length of 2 meters, when the pulling cable is not loaded.

A spacer ring 32 is fixed to the drum 9 to provide the latter with a surface coplanar with the right surface of the flange 20, so that the left end lamination 11 will be in a plane normal to the axis of the hub 20 while pressing against the spacer ring 32 and the flange 20'.

In order to achieve predetermined operating characteristics according to which the brake means will exert a given force over a given distance, the laminations l1 and 12 can be provided with different preselected friction materials, and this latter feature can be of significance when the structure is used as a safety device with cables of hoisting assemblies.

The handgrip 34 is fixed to the hub 20 so as to be rotatable therewith. By way of this manually engageable member 34 it is possible to manually turn the drum when the clutch teeth 27 of clutch member 25 do not engage the teeth of the clutch 28.

As shown in FIG. 2, the nut 22 carries a pointer 35 which coacts with a scale 36 situated on the housing shell 15. The graduations of the scale 36 are such that in every position of the pointer 35 there will be an indication of the effective pulling tension exerted by the cable.

In the illustrated example the inner end of the pull cable 3 is fixed to the drum 9 by way of a fixing element 39. Moreover, FIG. 2 illustrates how the housing 14, 15 is provided with a fastening means in the form of an eye or tube 37, The axis of this fastening sleeve or tube 37 is situated in a plane which contains the pulling, tensioned part of the cable 3 which projects beyond the housing 14, 15. As a result when the pullcable 3 is placed under tension in response to a pulling force, the energy-converting means 4 of the invention will not be subjected to any bending moments and a trouble-free running out of the cable 3 is assured. Thus it is unnecessary to provide the assembly with any guide rollers at the location where the cable moves from the interior to the exterior of the housing or holder means 14, 15. A metal loop 40 similar to a chain link extends into the eye or sleeve 37 so as to be freely swingable therein while fastened thereby to the housing I4, 15. This loop or link 40 is permanently connected with the connecting cable 5.

In order to use the assembly of the invention for pulling purposes, a sufficiently long leading part of the cable 3 is drawn out of the drum 9, assuming that the entire cable 3 has been wound onto the drum 9. A sufficiently long residual part of the cable 3 remains wound on the drum 9 at this time. This residual part is rendered readily recognizable by providing the exterior of the cable 3 with a suitable color or other marking 41 distinguishing that part of the cable which must remain on the drum 9 from that part which may be withdrawn therefrom during setting up of the assembly. Thus, when the operator sees the exterior portion 41 of the cable 3 he will immediately know that this is the beginning of that part of the cable which must remain as a reserve wound on the drum 9.

After the pulling cable 3 has been connected to the pulling vehicle 1 and the connecting cable 5 has been connected to the vehicle 2 which is to be pulled, the pulled vehicle 2 will normally assume the position shown in dotted lines in FIG. 1.

If it should occur during pulling of the vehicle that there is a sudden impact-type of load on the pull cable 3, for example, due to braking of the pulled vehicle 2, then assuming that the braking moment of the brake laminations in the assembly 4 is exceeded, the pull cable 3 will be pulled out of the assembly 4 and unwound from the drum 9 until the impact energy is absorbed by the energy-converting assembly 4 and converted into heat in the brake laminations. If for example the assembly is adjusted for a cable tension of 750 kp, then when a cable length of 2 meters is withdrawn from the drum 9 it is possible to absorb an impact energy on the order of 1,500 meters kp without any damage.

If now the pulling force on the pull cable 3 momentarily diminishes, for example by a slowing down in the movement of the pulling vehicle 1, then the spiral spring 10 retracts the cable into the housing 14, rewinding the cable onto the drum 9 until the original conditions are again achieved. This rewinding is rendered possible because the relatively flat surfaces of the teeth of the clutch members 25 and 28, which is to say their surfaces which are almost normal to the axis of the clutch, enable these teeth to be displaced out of engagement with each other in opposition to the spring 26 when the drum is rotated in the rewinding direction. When encountering relatively weak impacts, only a part of the marked section of the pull cable 3 will be withdrawn from the drum. In such a case it is not necessary after each impact to provide for rewinding of the cable again on the drum.

Of course it is not essential that the housing of the energyconverting assembly for the invention be connected to the load which is to be pulled by way of a cable or be connected to the pulling unit also by way of a cable. It is possible to provide a direct connection between these parts.

FIG. 5 shows an embodiment where pull rods in the form of a pair of telescopically assembled tubes 142 and 143 form the structure for connecting the assembly between the pulling and the pulled components with these telescoped tubes 142 and 143 being axially shiftable one with respect to the other. Thus, referring to FIG. 5, it will be seen that the elongated tube 143 is axially shiftable and telescoped within the outer tube 142. The ends of these tubes 142 and 143 which are directed away from each other are respectively provided with fastening eyes 144 and 145. The other end of the tube 142 is provided with an inwardly directed flange 146 while the inner end of the tube 143 is provided with an outwardly directed flange 147 which will engage the flange 146 so as to prevent the tubes 142 and 143 from being pulled completely apart from each other.

The inner tube 143 fixedly carries an axially extending rack 148. At the region of its end which is distant from its fastening eye 144 the tube 142 is provided with an axially extending slot 149 through which the rack 148 is freely accessible over a portion of its length. The tooth periphery of a rotary member 151, in the form of a gear, meshes with the rack 148 with the lower part of this tooth periphery, as viewed in FIG. 5, extending through the slot 149 into engagement with the rack 148. This rotary member 151 forms part of an assembly 150 of this embodiment which serves as an energy converter in the manner described above in connection with the energy converter 4. The gear 151 is supported for rotary movement within a housing or holder means 152 which is fixed to the outer tube 142 at the exterior thereof, and this gear 151 corresponds in its function to the drum 9 of the above-described embodiment of the invention.

The gear 151 is operatively connected as through a ratchettype clutch or the like, similar to that described above, with the brake means in the form of the friction laminations which may have a construction identical with that of FIGS. l-4. Moreover, this embodiment of FIG. 5 will also have a ratchet or other type of releasable clutch assembly between the brake laminations and the housing 152, so that without stressing the brake means the pair of tubes 142 and 143 may be shifted into a greater overlapping relationship, shortening the total length of the pair of telescope tubes. A return spring 153 may be provided for this purpose. This spring is shown within the outer tube 142 operatively connected to the left end of the latter and to the left end of the inner tube 143 so as to tend to pull these ends toward each other.

Although the invention is illustrated and described with reference to a plurality of preferred embodiments thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a plurality of preferred embodiments, but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

l. A device for towing a second vehicle by means of a first vehicle, comprising in combination,

a rotary winding drum,

holder means holding said drum for rotary movement,

flexible tension-transmitting means .wound onto said rotary winding drum for turning the latter in response to subjection of said tension-transmitting means to a pulling force,

a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum,

a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resist ing the rotary movement of said winding drum,

clutch means coacting with said rotary drum for freeing the latter for turning movement in a winding direction without any resistance from said first and second pluralities of brake laminations, and

drive means operatively connected with said rotary drum for urging the latter to turn in a direction opposite to the direction of turning of said rotary drum by the pulling force transmitted through said tension-transmitting means,

whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations.

2. The. combination of claim l and wherein an adjusting means coacts with said first and second pluralities of brake laminations for adjusting the braking force thereof.

3. The combination of claim 1 and wherein a means is provided for rendering said clutch means operative or inoperative.

4. The combination of claim 1 and wherein said drive means is in the form of a prestressed spring.

5. The combination of claim 1 and wherein said holder means is in the form of a housing.

6. The combination of claim 5 and wherein said rotary drum has a central hub portion, spring means connected between said hub portion and said housing for urging said rotary drum to turn in a direction opposite to that in which said rotary drum is urged by said tension-transmitting means, when the latter is subjected to the pulling force, and clutch means also situated between said hub portion of said rotary drum and said housing for releasing said rotary drumfor turning movement with respect to said housing in one direction of turning movement.

7. The combination of claim 1 and wherein said tensiontransmitting means is in the form of a flexible cable, said rotary drum having a winding chamber for receiving the cable and said chamber having a magnitude sufficiently great to accommodate the entire cable.

8. The combination of claim 1 and wherein a fastening means is operatively connected to said holder means for fastening the latter to a vehicle which is to be towed, and said fastening means being aligned with said bendable element which extends from said rotary drum and which is under tension during use of the assembly.

9. The combination of claim 1 and wherein said tensiontransmitting means is in the form of an elongated bendable element having an outer portion for connecting the element to a pulling source while the remainder of said bendable element is of an exterior appearance different from said outer portion thereof so as to be readily recognizable.

10. A device for towing a second vehicle by means of a first vehicle, comprising in combination,

a rotary winding drum,

holder means holding said drum for rotary movement,

flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection of said tension-transmitting means to a pulling force,

a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum,

a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum,

and a housing for housing said rotary drum, said rotary drum including a rotary member having a toothed periphery, and said tension-transmitting means including a rack meshing with said toothed periphery of said rotary member so that in response to movement of said rack said rotary member turns,

whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations.

11. The combination of claim 10 wherein said tension-transmitting means includes a bar assembly having an elongated portion carrying said rack.

12. A device for towing a second vehicle by means of a first vehicle, comprising in combination,

a rotary winding drum,

holder means holding said drum for rotary movement,

flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection said tension-transmitting means to a pulling force,

a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum,

a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum,

said rotary drum has a portion of annular configuration surrounding a given space, and said first and second pluralities of brake laminations being situated within said space, and

a clutch means coacting with said rotary drum for freeing the latter for turning movement in a winding direction without any resistance from said first and second pluralities of brake laminations,

whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations.

13. A device for towing a second vehicle by means of a first vehicle, comprising in combination,

a rotary winding drum,

holder means holding said drum for rotary movement,

flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection of said tension-transmitting means to a pulling force,

a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum,

a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum,

said rotary drum has a portion of annular configuration surrounding a given space, and said first and second pluralities of brake laminations being situated within said space, and

drive means operatively connected with said rotary drum for urging the latter to turn in a direction opposite to the direction of turning of said rotary drum by the pulling force transmitted through said tension-transmitting means,

whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations.

14. A device for towing a second vehicle by means of a first vehicle, comprising in combination,

a rotary winding drum,

holder means holding said drum for rotary movement,

flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection of said tension-transmitting means to a pulling force,

a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum,

a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum,

clutch means coacting with said rotary drum for freeing the latter for turning movement in a winding direction without any resistance from said first and second pluralities of brake laminations,

drive means operatively connected with said rotary drum for urging the latter to turn in a direction opposite to the direction of turning of said rotary drum by the pulling force transmitted through said tension-transmitting means, and

said rotary drum has a portion of annular configuration surrounding a given space, and said first and second pluralities of brake laminations being situated within said space,

whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations. 

1. A device for towing a second vehicle by means of a first vehicle, comprising in combination, a rotary winding drum, holder means holding said drum for rotary movement, flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection of said tension-transmitting means to a pulling force, a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum, a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum, clutch means coacting with said rotary drum for freeing the latter for turning movement in a winding direction without any resistance from said first and second pluralities of brake laminations, and drive means operatively connected with said rotary drum for urging the latter to turn in a direction opposite to the direction of turning of said rotary drum by the pulling force transmitted through said tension-transmitting means, whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations.
 2. The combination of claim 1 and wherein an adjusting means coacts with said first and second pluralities of brake laminations for adjusting the braking force thereof.
 3. The combination of claim 1 and wherein a means is provided for rendering said clutch means operative or inopErative.
 4. The combination of claim 1 and wherein said drive means is in the form of a prestressed spring.
 5. The combination of claim 1 and wherein said holder means is in the form of a housing.
 6. The combination of claim 5 and wherein said rotary drum has a central hub portion, spring means connected between said hub portion and said housing for urging said rotary drum to turn in a direction opposite to that in which said rotary drum is urged by said tension-transmitting means, when the latter is subjected to the pulling force, and clutch means also situated between said hub portion of said rotary drum and said housing for releasing said rotary drum for turning movement with respect to said housing in one direction of turning movement.
 7. The combination of claim 1 and wherein said tension-transmitting means is in the form of a flexible cable, said rotary drum having a winding chamber for receiving the cable and said chamber having a magnitude sufficiently great to accommodate the entire cable.
 8. The combination of claim 1 and wherein a fastening means is operatively connected to said holder means for fastening the latter to a vehicle which is to be towed, and said fastening means being aligned with said bendable element which extends from said rotary drum and which is under tension during use of the assembly.
 9. The combination of claim 1 and wherein said tension-transmitting means is in the form of an elongated bendable element having an outer portion for connecting the element to a pulling source while the remainder of said bendable element is of an exterior appearance different from said outer portion thereof so as to be readily recognizable.
 10. A device for towing a second vehicle by means of a first vehicle, comprising in combination, a rotary winding drum, holder means holding said drum for rotary movement, flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection of said tension-transmitting means to a pulling force, a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum, a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum, and a housing for housing said rotary drum, said rotary drum including a rotary member having a toothed periphery, and said tension-transmitting means including a rack meshing with said toothed periphery of said rotary member so that in response to movement of said rack said rotary member turns, whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations.
 11. The combination of claim 10 wherein said tension-transmitting means includes a bar assembly having an elongated portion carrying said rack.
 12. A device for towing a second vehicle by means of a first vehicle, comprising in combination, a rotary winding drum, holder means holding said drum for rotary movement, flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection said tension-transmitting means to a pulling force, a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum, a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum, said rotary drum has a portion of annular configuration surrounding a given space, and said first and second pluralities of brake laminations being situated within said space, and a clutch means coacting with said rotary drum for Freeing the latter for turning movement in a winding direction without any resistance from said first and second pluralities of brake laminations, whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations.
 13. A device for towing a second vehicle by means of a first vehicle, comprising in combination, a rotary winding drum, holder means holding said drum for rotary movement, flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection of said tension-transmitting means to a pulling force, a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum, a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum, said rotary drum has a portion of annular configuration surrounding a given space, and said first and second pluralities of brake laminations being situated within said space, and drive means operatively connected with said rotary drum for urging the latter to turn in a direction opposite to the direction of turning of said rotary drum by the pulling force transmitted through said tension-transmitting means, whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations.
 14. A device for towing a second vehicle by means of a first vehicle, comprising in combination, a rotary winding drum, holder means holding said drum for rotary movement, flexible tension-transmitting means wound onto said rotary winding drum for turning the latter in response to subjection of said tension-transmitting means to a pulling force, a first plurality of juxtaposed brake laminations operatively connected to said rotary winding drum, a second plurality of juxtaposed brake laminations operatively connected to said holder means and frictionally engaging said first plurality of brake laminations for resisting the rotary movement of said winding drum, clutch means coacting with said rotary drum for freeing the latter for turning movement in a winding direction without any resistance from said first and second pluralities of brake laminations, drive means operatively connected with said rotary drum for urging the latter to turn in a direction opposite to the direction of turning of said rotary drum by the pulling force transmitted through said tension-transmitting means, and said rotary drum has a portion of annular configuration surrounding a given space, and said first and second pluralities of brake laminations being situated within said space, whereby when the tension of the pulling force is transmitted through said tension-transmitting means to said winding drum to turn the latter, the force is converted into heat energy by the frictional engagement of said first and second pluralities of brake laminations. 